1. Field of the Invention
The present invention relates to projection, illumination and lighting, including but not limited to artistic lighting systems for creating or enhancing a particular mood and artistic effects creation using a gobo.
2. Description of the Related Art
It is oftentimes desired to project images, patterns, or colored light onto a background, wall, or other structure in an entertainment and an architectural setting. Luminaires or lighting units have been utilized in combination with images or patterns to create these projections or colored light. A common term of art used for a substrate, screen, mat, or other material having an image or pattern for projection by light is “gobo.” The name gobo is thought to have been derived from the concept of “Go between” or “Goes before optics”.
Gobos are a form of illuminated panel, which include images or patterns that are sharply focused, for example, corporate logos, regular or irregular patterns, or elements of stage scenery. Alternatively, the images or patterns on the gobos may be designed to suggest a mood or environment on a stage, such as a pattern suggesting light passing through leaves on a tree.
Gobos are used in theatres, television studios, concert venues, theme parks, night clubs, retail premises, offices, exhibition halls, and other venues. Gobos may be manufactured from a range of materials, such as metal, glass or plastic and are typically produced in a range of standard sizes and patterns designed to fit common luminaires so that they are easily inserted and removed in the luminaire. They are often used with stage lighting instruments to manipulate the shape of the light that is cast over a space or object. A metal gobo with patterned holes allows only the desired shape or pattern of light through, casting a specific pattern of light and shadow into the space.
Though the term “gobo” has come to generally refer to any device which produces patterns of light and shadow, in theatrical lighting applications the term more specifically refers to a device placed in ‘the gate’ or at the ‘point of focus’ between the light source and the lenses (or other optics). This placement is important because it allows a pattern with crisp, sharp edges to be projected onto a surface on the stage. Gobos placed after the optics do not have the option of such fine focus, and are more precisely called “flags” or “cookies”.
Gobos may be used, in connection with projectors and simpler light sources, to create lighting scenes in a theatrical application. Simple gobos, incorporated into automated lighting systems, are popular at nightclubs and other musical venues to create moving shapes. Gobos may also be used for architectural lighting, as well as in interior design, as in projecting a company logo on a wall or other feature.
Gobos can be made from various materials. Common types include steel, glass and plastic/transparency gobos. Steel gobos use a metal template from which the image is cut, and are generally the most sturdy of the common gobo types, but often require modifications to the original design called bridging in order to display correctly. In order to correctly represent the letter “O ” for example, small tabs or bridges must be made in order to keep the metal tab in the middle of the letter supported. This effect may be undesirable in more intricate patterns or designs.
Glass gobos are made from transparent glass with a partial mirror coating to block the light and produce “black” areas in the projected image. This eliminates any need for bridging, since the glass itself is the support, and allows more intricate images to be produced. Glass gobos can also include colored areas (much like stained glass windows), whether by multiple layers of dichroic glass (one for each color) glued on an aluminum or chrome coated black and white gobo, or by varying the thickness of the dichroic coating (and therefore the color) in a controlled way on a single piece of glass, making it possible to turn a color photo into a glass gobo. Glass gobos generally offer the highest image fidelity but are the most fragile. Usually, to create a glass gobo laser ablation or photo etching techniques are used.
Plastic gobos or transparency gobos can be used in LED ellipsoidal spotlights. These “LED Only” plastic gobos can be full color (like a glass gobo), but without the delicate nature.
In the past plastic gobos had been generally custom made—for when a pattern is needed in color and glass does not suffice. However, in a “traditional” (tungsten/halogen) light fixture, the focus point where a gobo must be placed is usually extremely hot, so these thin plastic films generally need to be used with special cooling elements to prevent them from being melted. A lapse in the cooling apparatus, even for just a few seconds, can cause plastic gobos in a traditional lighting instrument to be ruined.
Gobos are often used in weddings and corporate events to add a personal touch to the look of an event. Company logos, the couple's names, or just about any artwork can be turned into a projected image. Common locations that gobos are projected in corporate/wedding situations are: the wall behind the head table, the center of the dance floor, on the floor in front of the main entrance, and the most dominant wall.
The gobo is placed in the focal plane of the lantern (generally an ellipsoidal reflector spotlight). The gobo is inserted upside-down and back-to-front. The desired pattern is then projected, by the lantern, onto whatever surface it is pointed at, such as a wall or a dance floor.
What is needed is a method for manufacturing a resilient gobo in an economic manner.